U.S. patent application number 13/012380 was filed with the patent office on 2012-07-26 for assembly for preventing fluid flow.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Rebecca Evelyn Hefner, Victor John Morgan, Stephen Gerard Pope.
Application Number | 20120189435 13/012380 |
Document ID | / |
Family ID | 46467245 |
Filed Date | 2012-07-26 |
United States Patent
Application |
20120189435 |
Kind Code |
A1 |
Morgan; Victor John ; et
al. |
July 26, 2012 |
ASSEMBLY FOR PREVENTING FLUID FLOW
Abstract
According to one aspect of the invention, an assembly for
preventing fluid flow between turbine components includes a shim
and a first woven wire mesh layer that includes a first surface
coupled to a first side of the shim and a second surface of the
woven wire mesh layer opposite the first surface. The assembly also
includes a first outer layer coupled to the second surface of the
woven wire mesh layer, where the first outer layer includes a high
temperature non-metallic material.
Inventors: |
Morgan; Victor John;
(Simpsonville, SC) ; Hefner; Rebecca Evelyn;
(Greenville, SC) ; Pope; Stephen Gerard; (Roebuck,
SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
46467245 |
Appl. No.: |
13/012380 |
Filed: |
January 24, 2011 |
Current U.S.
Class: |
415/174.2 |
Current CPC
Class: |
F05C 2203/00 20130101;
C04B 14/20 20130101; F01D 11/005 20130101; F01D 11/003
20130101 |
Class at
Publication: |
415/174.2 |
International
Class: |
F01D 11/00 20060101
F01D011/00 |
Claims
1. An assembly for preventing fluid flow between turbine
components, the assembly comprising: a shim; a first woven wire
mesh layer comprising a first surface coupled to a first side of
the shim and a second surface of the woven wire mesh layer opposite
the first surface; and a first outer layer coupled to the second
surface of the woven wire mesh layer, where the first outer layer
comprises a high temperature non-metallic material.
2. The assembly of claim 1, wherein the first woven wire mesh layer
comprises one or more woven wire mesh layers.
3. The assembly of claim 1, wherein the shim comprises a member
with raised longitudinal edges, wherein the raised longitudinal
edges form at least one recess on the first side of the shim.
4. The assembly of claim 1, wherein the assembly is configured to
sealingly engage the turbine components, thereby preventing fluid
flow.
5. The assembly of claim 1, comprising a second woven wire mesh
layer comprising a first surface coupled to a second side of the
shim opposite the first side.
6. The assembly of claim 5, comprising a second outer layer coupled
to a second surface of the second woven wire mesh layer, the second
surface being opposite the first surface of the second woven wire
mesh layer and the second outer layer comprising the high
temperature non-metallic material.
7. The assembly of claim 1, wherein the high temperature
non-metallic material comprises a mica based material.
8. The assembly of claim 1, wherein the high temperature
non-metallic material comprises a graphite based material.
9. An assembly for preventing fluid flow between stator parts of a
gas turbine, the assembly comprising: a substantially rigid
metallic body; a first outer layer coupled to a first surface of
the substantially rigid metallic body; and a second outer layer
coupled to a second surface of the substantially rigid metallic
body, the second surface being opposite the first surface and the
first and second outer layers comprising a high temperature
non-metallic material.
10. The assembly of claim 9, wherein the high temperature
non-metallic material comprises a mica based material.
11. The assembly of claim 9, wherein the high temperature
non-metallic material comprises a graphite based material.
12. A gas turbine comprising: a first turbine component; a second
turbine component adjacent to the first turbine component; a cavity
formed between the first and second turbine components; and a shim
assembly placed within the cavity to prevent fluid flow between the
first and second turbine components, the shim assembly comprising a
high temperature non-metallic layer disposed on a metallic shim
member.
13. The gas turbine of claim 12, wherein the first and second
turbine components comprise stator components.
14. The gas turbine of claim 12, wherein the high temperature
non-metallic layer comprises a mica based material.
15. The gas turbine of claim 12, wherein the shim assembly
comprises a metallic woven wire mesh layer disposed between the
high temperature non-metallic layer and the metallic shim
member.
16. The gas turbine of claim 12, wherein the metallic shim member
comprises a member with raised longitudinal edges.
17. The gas turbine of claim 16, wherein the raised longitudinal
edges form at least one recess in the metallic shim member.
18. The gas turbine of claim 12, wherein the high temperature
non-metallic layer comprises a layer disposed on each side of the
shim assembly.
19. The gas turbine of claim 12, wherein the shim assembly
comprises a plurality of metallic woven wire mesh layers disposed
on each side of the metallic shim member, wherein the metallic
woven wire mesh layers are disposed between the high temperature
non-metallic layer and the metallic shim member.
20. The gas turbine of claim 12, wherein the high temperature
non-metallic layer comprises a graphite based material.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to gas turbines.
More particularly, the subject matter relates to seals between
components of gas turbines.
[0002] In a gas turbine, a combustor converts chemical energy of a
fuel or an air-fuel mixture into thermal energy. The thermal energy
is conveyed by a fluid, often compressed air from a compressor, to
a turbine where the thermal energy is converted to mechanical
energy. Leakage of the compressed air between turbine parts or
components causes reduced power output and lower efficiency for the
turbine. Leaks may be caused by thermal expansion of certain
components and relative movement between components during
operation of the gas turbine. Accordingly, reducing gas leaks
between turbine components can improve efficiency and performance
of the turbine.
BRIEF DESCRIPTION OF THE INVENTION
[0003] According to one aspect of the invention, an assembly for
preventing fluid flow between turbine components includes a shim
and a first woven wire mesh layer that includes a first surface
coupled to a first side of the shim and a second surface opposite
the first surface. The assembly also includes a first outer layer
coupled to the second surface of the woven wire mesh layer opposite
the first surface. The assembly also includes a first outer layer
coupled to the second surface of the woven wire mesh layer, where
the first outer layer includes a high temperature non-metallic
material.
[0004] According to another aspect of the invention, a gas turbine
includes a first turbine component, a second turbine component
adjacent to the first turbine component and a cavity formed between
the first and second turbine components. The gas turbine also
includes a shim assembly placed within the cavity to prevent fluid
flow between the first and second turbine components, the shim
assembly comprising a high temperature non-metallic layer disposed
on a metallic shim member
[0005] These and other advantages and features will become more
apparent from the following description taken in conjunction with
the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0006] The subject matter, which is regarded as the invention, is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features, and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0007] FIG. 1 is a schematic drawing of an embodiment of a gas
turbine engine, including a combustor, fuel nozzle, compressor and
turbine;
[0008] FIG. 2 is a side view of an embodiment of a portion of a gas
turbine, including components along a hot gas path;
[0009] FIG. 3 is a sectional side view of an embodiment of a seal
assembly; and
[0010] FIG. 4 is a sectional side view of another embodiment of a
seal assembly.
[0011] The detailed description explains embodiments of the
invention, together with advantages and features, by way of example
with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a schematic diagram of an embodiment of a gas
turbine system 100. The system 100 includes a compressor 102, a
combustor 104, a turbine 106, a shaft 108 and a fuel nozzle 110. In
an embodiment, the system 100 may include a plurality of
compressors 102, combustors 104, turbines 106, shafts 108 and fuel
nozzles 110. The compressor 102 and turbine 106 are coupled by the
shaft 108. The shaft 108 may be a single shaft or a plurality of
shaft segments coupled together to form shaft 108.
[0013] In an aspect, the combustor 104 uses liquid and/or gas fuel,
such as natural gas or a hydrogen rich synthetic gas, to run the
engine. For example, fuel nozzles 110 are in fluid communication
with an air supply and a fuel supply 112. The fuel nozzles 110
create an air-fuel mixture, and discharge the air-fuel mixture into
the combustor 104, thereby causing a combustion that heats a
pressurized gas. The combustor 100 directs the hot pressurized
exhaust gas through a transition piece into a turbine nozzle (or
"stage one nozzle") and then a turbine bucket, causing turbine 106
rotation. The rotation of turbine 106 causes the shaft 108 to
rotate, thereby compressing the air as it flows into the compressor
102. The turbine components or parts are joined by seals or seal
assemblies configured to allow for thermal expansion and relative
movement of the parts while preventing leakage of the gas.
Specifically, reducing leakage of compressed gas flow between
turbine components increases hot gas flow along the desired path,
enabling work to be extracted from more of the hot gas, leading to
improved turbine efficiency. Seals and seal assemblies for
placement between turbine parts are discussed in detail below with
reference to FIGS. 2-4.
[0014] FIG. 2 is a side view of an embodiment of a portion of a gas
turbine 200, showing components along a hot gas 202 path or flow.
The gas turbine 200 includes a nozzle 204, bucket 206 (also called
a "blade" or "vane"), nozzle 208 and shroud 210, wherein the hot
gas 202 flows through the vane or airfoil-shaped nozzles and
buckets to cause rotation of rotors about an axis 212. As depicted,
the bucket 206 and shroud 210 are part of a rotor assembly between
two stators, wherein the stator assemblies include nozzles 204 and
208. The nozzle 204 and bucket 206 are described as stage one
components, while nozzle 208 is a stage two component of the
turbine 200. The nozzle 208 is positioned on a diaphragm 214 of the
stator assembly. A seal assembly 216 is at least partially
positioned in the diaphragm 214 to prevent leakage of hot gas 202
from the path that includes buckets 206 and nozzles 204 and 208.
The seal assembly 216 is positioned between adjacent diaphragm
components that are circumferentially positioned about axis 212.
The gas turbine 200 may include a plurality of seal assemblies 216
located between adjacent components to prevent leakage of hot gas
202 from the desired flow path. Exemplary turbine components
include stator components, rotor components and transition piece
components.
[0015] FIG. 3 is a side sectional view of the seal assembly 216
positioned between adjacent turbine components or parts 214 and
300. The seal assembly 216 is positioned in a cavity 302 formed
between the turbine components 214 and 300. The seal assembly 216
includes a shim 304, first layer 306, second layer 308 and outer
layer 310. In an embodiment, the shim 304 is member formed from a
high temperature material, such as a metal alloy, stainless steel,
or nickel-based alloy. The shim 304 member includes a middle
portion with two surfaces and raised longitudinal edges, wherein
recesses are formed by the raised longitudinal edges for placement
of the layers 306 and 308. The first layer 306 and second layer 308
each comprise a metallic woven wire mesh or cloth metallic
material. As depicted, the first layer 306 and second layer 308 are
positioned on each surface or side of the shim 304. The first layer
306 and second layer 308 are coupled to one another and the shim
304 via high temperature couplings, such as welds, brazes or high
temperature adhesives. The outer layer 310 comprises a high
temperature non-metallic material that is configured to improved
sealing of the seal assembly 216. In one embodiment, the outer
layer 310 comprises a mica-based or graphite-based material.
[0016] In aspects, the seal assembly 216 includes the first layer
306, second layer 308 and outer layer 310 positioned on one surface
of the shim 304. Further, another embodiment of seal assembly
includes the first layer 306 and outer layer 310 positioned on one
or both surfaces of the shim 304, wherein the second layer 308 is
not included. In yet another embodiment, the outer layer 310 is
disposed on the shim 304, without first layer 306 or second layer
310. The outer layer 310 is coupled to the components of seal
assembly 216 by any suitable high temperature-resistant mechanism,
such as high temperature adhesives or high strength durable
fasteners. Alternatively, one or more portions of the shim 304 can
be wrapped to substantially surround or constrain the outer layer
310. In an embodiment, as hot gas flows through gas turbine 200
(FIG. 2), the gas flow pressures the seal assembly 216 to move in a
direction 312 into contact with turbine components 214 and 300.
Further, when contacting the components 214 and 300, the high
temperature non-metallic material of outer layer 310 provides and
reduction of gas flow through the seal assembly 216 by reducing the
effective gap between the seal assembly 216 and the components 214
and 300.
[0017] FIG. 4 is a side sectional view of an exemplary seal
assembly 400 positioned between adjacent turbine components or
parts 408 and 410. The seal assembly 400 is positioned in a cavity
402 formed between the turbine components 408 and 410. The seal
assembly 400 includes outer layer 404 disposed on base layer 406.
The outer layer 404 comprises a high temperature non-metallic
material that is configured to improved sealing of the seal
assembly 400. In one embodiment, the outer layer 404 comprises a
mica-based or graphite-based material. The base layer 406 comprises
a high temperature material, such as a metal alloy, stainless
steel, or nickel-based alloy. The outer layer 404 is coupled to the
base layer 406 via any suitable high temperature-resistant
mechanism, such as high temperature adhesives or high strength
fasteners. In an embodiment, as hot gas flows through gas turbine
200 (FIG. 2), the gas flow pressures the seal assembly 400 to move
in a direction 412 into contact with turbine components 408 and
410. When contacting the components 408 and 410, the high
temperature non-metallic material of outer layer 404 provides a
reduced effective gap between components and reduces gas flow
through the seal assembly 400. In an embodiment, the outer layer
404 comprises a mica-based or graphite-based material. An exemplary
outer layer 404 is a non-metallic material configured to provide a
seal between turbine components at high temperatures, such as
greater than about 700 degrees Fahrenheit.
[0018] As depicted in FIGS. 3 and 4, the high temperature
non-metallic material of outer layer 310 and 404 reduces fluid flow
through the seal assemblies 216 and 400. The high temperature
non-metallic material layer is disposed on one or more sides of any
type of static-static seal, such as those including the shim 304
and mesh layers 306, 308 as well as base layer 406. Fluid flow,
including hot gas flowing through the turbine 200 (FIG. 2), is
reduced due to improved contact and sealing provided by outer layer
310 and 404 when contacting the turbine components (214, 300, 408,
410). In addition, exemplary embodiments of the shim 304 and base
layer 406 may be referred to as a substantially rigid metallic body
wherein the outer layers 310 and 404 are disposed on the shim 304
and base layer 406, respectively. As depicted in FIG. 3, the outer
layer 310 is disposed on one or more layers, such as first layer
306 and second layer 308. As shown in FIGS. 3 and 4, the seal
assemblies 216 and 400 are configured to sealingly engage one or
more turbine parts (214, 300, 408, 410) to prevent fluid flow
through cavities 302 and 402. For example, the seal assembly 216
may contact an inner wall 314 of the turbine parts 214 and 300 to
prevent or reduce fluid flow. In embodiments, the high temperature
non-metallic material is substantially impermeable, even at
elevated temperatures, thereby providing improved contact area with
the turbine components and a resulting improved seal. The increased
sealing effectiveness of the seal assembly 216 results from a
decreased effective leakage area provided by the non-metallic
material. The decreased effective leakage area is a result of a
larger contact area and small amount of deformation of the layer
high temperature non-metallic material.
[0019] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *